I. Field of the Disclosure
The technology of the disclosure relates generally to low-power operations to reduce power consumption in electronic systems.
II. Background
Mobile communication devices have become increasingly common in current society. The prevalence of these mobile communication devices is driven in part by the many functions that are now enabled on such devices. Demand for such functions increases the processing capability requirements for the mobile communication devices. As a result, the mobile communication devices have evolved from being purely communication tools into sophisticated mobile entertainment centers.
Concurrent with the rise in the processing capability of the mobile communication devices is the increase in power consumption by the mobile communication devices. Low-power operations are commonly employed by the mobile communication devices to conserve power and prolong battery life. During the low-power operations, the mobile communication devices can opportunistically switch off electronic circuits that are idle or underutilized. For example, an input/output (I/O) circuit may be switched off when there is no data to transmit and switched back on when data becomes available for transmission. With more and more multi-frequency reference clocks being used to control the electronic circuits, the reference clocks associated with the electronic circuits are often switched off or configured to operate at a reduced frequency when the electronic circuits are placed in low-power operations.
When the electronic circuit exits the low-power operations, the electronic circuit will not become operational until the associated reference clocks fully ramp up and stabilize. As a result, the electronic circuit may be forced to exit the low-power operations earlier than needed to accommodate for the reference clock ramp-up and stabilization delays. Such early exit reduces the effectiveness of the low-power operations. Furthermore, premature switching to the associated reference clock (i.e., before the associated reference clock is stable) may result in metastability in the electronic circuit.